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From: mg@asp.camb.inmet.com (Mitch Gart)
Subject: Re: Magnavox consultant trashes Ada tools in IEEE Computer
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References: <9410272051.AA16079@ajpo.sei.cmu.edu>
Date: Fri, 28 Oct 1994 15:12:49 GMT
Date: 1994-10-28T15:12:49+00:00
List-Id: <comp.lang.ada>

One reason for the long compile times was a bad interaction between
the Rational and Alsys toolsets.  Magnavox was composing their code
with Rational, then fairly late in the development cycle compiling it 
with Alsys.  Something about the Rational environment or editor caused 
Magnavox to go the direction of using lots of very deeply nested 
subunits, and lots of parent and child libraries.  Rational subsystems 
were mapped into Alsys parent-child libraries.  They were using a 
library structure with parent-child-grandchild... to at least 10 levels 
deep.  In the end they had a huge Ada program which was 

- as big or bigger than any program that had ever gone through the
  Alsys compiler

- structured in a very unusual way, with sub-libraries and subunits
  used much more heavily than "normal", whatever normal is

This combination seems to have brought the compile-time performance
of the Alsys compiler to its knees.  It seems to have exposed a
performance problem with very big programs whose library structure is
nested in this unusual way.

Whose fault is it, Magnavox, Rational, Alsys, Ada?  I don't know,
but it's too bad this had to get discussed in such a negative way.

	Mitch Gart